Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false) give the safety profile, and the description adds non-obvious context that is not in any structured field: the tool deliberately refuses raw payloads, signature values, and signing secrets. That sanitization constraint is genuinely useful behavioral information for an agent deciding what to pass.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single tight sentence with the scope constraint front-loaded and no filler. It is efficient, though its brevity is partly achieved by omitting input guidance rather than by disciplined editing.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be described. Still, for a 5-parameter, 0%-coverage diagnostic tool, the description omits what each input should contain and any prerequisites or typical error classes, leaving the agent with limited operational guidance.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% across 5 parameters, so the description must compensate and largely does not. It only hints at exclusions (no raw payload/signature/secret), leaving context, retry_count, payload_size_bytes, signature_header_present and the required error_message format entirely unexplained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (diagnose) and resource (webhook signature/delivery failure), and the resource scope distinguishes it from siblings like diagnose_api_auth_401 and diagnose_json_schema_failure, though it never names them explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the name and description: call it when a webhook signature or delivery fails. However, there is no explicit when-to-use vs. when-not guidance and no routing to the sibling diagnose_* tools, which an agent must infer from tool names alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.